I was watching some AEAC videos on YouTube and discovered something interesting about pellet penetration versus springer power. It seems that, in 4.5mm, at around 30 metres, certain combinations of common pellet types shot from a 5.5 foot-pounds spring air rifle can penetrate the same distance into a gel target as ones shot from a 16 foot-pounds air rifle also in 4.5 mm.
I found this to be very interesting as someone who likes to eliminate back yard gel targets; though, it seems to me that the 16 foot-pounds air rifle will clearly deliver a more forceful shock effect on the target allowing for a faster knockout blow. Nevertheless the 5.5 foot-pounds gun will make the same length of hole through the subject. The guns reviewed are the HW 30s and the Diana N-Tec 340.
The links to the videos are
Diana N-Tec https://www.youtube.com/watch?v=i8ptWO3qupI&t=602s